Controller for Inhalation Device

CROSS REFERENCES TO RELATED APPLICATION

The present invention contains subject matter related to Japanese Patent Application No. 2020-038095 filed in the Japan Patent Office on Mar. 5, 2020, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a controller for an inhalation device.

Description of the Related Art

Japanese Patent Laid-Open No. 2018-514191 describes an aerosol generation system including an electric heater configured to heat an aerosol forming base. The system detects, based on a change in the resistance of the heater, an increase of the speed of the temperature change of the heater which occurs when the aerosol forming base in a cartridge is nearly used up. More specifically, a resistance R 1 formed by a parasitic resistance RP of an electrical contact of the heater and a resistance R 0 of a heater filament is measured as an initial resistance value before any heating is performed (before the heater is activated for the first time), and a change ΔR (=R 2 −R 1 ) of the resistance of the heater at time t 1 from supply of power to the heater is calculated using the initial resistance value R 1 as a reference. R 2 is the resistance of the heater at time t 1 . Using the calculated change ΔR of the resistance of the heater, an abrupt increase in the temperature of the heater, which indicates a dry state of the heater filament, is detected.

In Japanese Patent Laid-Open No. 2018-514191, the resistance value R 1 serving as the reference of heater temperature detection is measured before any heating is performed (before the heater is activated for the first time) and used in all subsequent heater temperature detection processes. However, the present inventor found that the reference resistance value of the heater corresponding to a predetermined temperature (reference temperature) of the heater varies in, for example, each puff operation of a user because of the parasitic resistance (contact resistance) of the electrical contact of the heater, and the like. If the reference resistance value corresponding to the reference temperature of the heater changes, it may be difficult to accurately detect the temperature of the heater.

SUMMARY OF THE INVENTION

The present invention provides a technique advantageous in, for example, accurately detecting the temperature of a heater that heats an aerosol source.

According to one aspect of the present invention, there is provided a controller for an inhalation device, comprising: a power supplier configured to supply power to a heater used to heat and atomize an aerosol source; a detection circuit configured to detect a resistance value of the heater; and a processor configured to execute heating processing of heating the aerosol source by controlling the power supplier to supply the power to the heater in accordance with reception of an atomization request of the aerosol source, wherein the processor controls the heating processing based on the resistance value of the heater detected using the detection circuit during the heating processing, a reference temperature of the heater, and a reference resistance value of the heater at the reference temperature, and updates the reference resistance value by the resistance value of the heater detected using the detection circuit after an end of the heating processing and before the reception of the next atomization request.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view schematically showing the arrangement of an inhalation device according to an embodiment;

FIG. 2 is a view showing the first arrangement example of an electric component;

FIG. 3 is a view showing the second arrangement example of the electric component;

FIG. 4 is a view showing the third arrangement example of the electric component;

FIGS. 5 A- 5 B are flowcharts showing the operation of the inhalation device according to an embodiment;

FIGS. 6 A- 6 B are flowcharts showing detection associated processing of the inhalation device according to an embodiment;

FIG. 7 is a view showing a verification example of the temporal changes of the temperature and the resistance value of a heater;

FIG. 8 is a view showing a verification example of the temporal changes of the temperature and the resistance value of the heater;

FIG. 9 is a view showing a verification example of the temporal changes of the temperature and the resistance value of the heater during natural cooling;

FIG. 10 is a view showing a verification example of the temporal changes of the temperature and the resistance value of the heater during natural cooling;

FIG. 11 is a flowchart showing the first example for providing details of cooling determination processing;

FIG. 12 is a flowchart showing the second example for providing details of cooling determination processing;

FIGS. 13 A- 13 B are flowcharts showing another example of detection associated processing of the inhalation device;

FIG. 14 is a view showing an example of operation modes of a processor; and

FIG. 15 is a view showing a detailed example in which calculation of a resistance value R HTR of a heater is implemented by an analog circuit.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention, and limitation is not made an invention that requires all combinations of features described in the embodiments. Two or more of the multiple features described in the embodiments may be combined as appropriate. Furthermore, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.

FIG. 1 schematically shows the arrangement of an inhalation device (inhalator) 100 according to an embodiment. The inhalation device can be configured to provide a gas containing an aerosol or a gas containing an aerosol and a flavor substance to a user via a mouthpiece portion 130 in accordance with an inhalation operation of the user. The inhalation device 100 can include a controller 102 and an atomizer 104 . The inhalation device 100 can include a holding portion 103 that holds the atomizer 104 in a detachable state. The controller 102 can be understood as an inhalation device controller. The atomizer 104 can be configured to atomize an aerosol source. The aerosol source can be, for example, a liquid such as a polyhydric alcohol such as glycerin or propylene glycol. Alternatively, the aerosol source may contain a drug. The aerosol source may be a liquid, a solid, or a mixture of a liquid and a solid. A vapor source such as water may be used in place of the aerosol source.

The inhalation device 100 may further include a capsule 106 including a flavor source 131 , and the atomizer 104 can include a capsule holder 105 that holds the capsule 106 in a detachable state. The capsule holder 105 may be included not in the atomizer 104 but in the controller 102 . The flavor source 131 can be, for example, a molded body formed by molding a tobacco material. Alternatively, the flavor source 131 may be formed by a plant (for example, mint, herb, Chinese herb, coffee bean, and the like) other than tobacco. A flavor such as menthol may be added to the flavor source. The flavor source 131 may be added to the aerosol source.

The controller 102 can include an electric component 110 . The electric component 110 can include a user interface 116 . Alternatively, it may be understood that the controller 102 includes the electric component 110 and the user interface 116 . The user interface 116 can include, for example, a display unit DISP (for example, a light emitting element such as an LED and/or an image display device such as an LCD) and/or an operation unit OP (for example, a switch such as a button switch and/or a touch display).

The holding portion 103 of the controller 102 can include a first electrical contact 111 and a second electrical contact 112 . In a state in which the atomizer 104 is held by the holding portion 103 , the first electrical contact 111 of the holding portion 103 can contact a third electrical contact 123 of the atomizer 104 , and the second electrical contact 112 of the holding portion 103 can contact a fourth electrical contact 124 of the atomizer 104 . The controller 102 can supply power to the atomizer 104 via the first electrical contact 111 and the second electrical contact 112 .

The atomizer 104 can include the third electrical contact 123 and the fourth electrical contact 124 described above. In addition, the atomizer 104 can include a heater 127 that heats the aerosol source, a container 125 that holds the aerosol source, and a transport portion (wick) 126 that transports the aerosol source held by the container 125 to a heating area by the heater 127 . At least a part of the heating area can be arranged in a channel 128 provided in the atomizer 104 . The first electrical contact 111 , the third electrical contact 123 , the heater 127 , the fourth electrical contact 124 , and the second electrical contact 112 form a current path configured to flow a current to the heater 127 . The transport portion 126 can be made of, for example, a fiber material or a porous material.

As described above, the atomizer 104 can include the capsule holder 105 that detachably holds the capsule 106 . In an example, the capsule holder 105 can hold the capsule 106 such that a part of the capsule 106 is stored in the capsule holder 105 or the atomizer 104 , and the other part is exposed. The user can inhale a gas containing an aerosol by holding the mouthpiece portion 130 in the mouth. When the mouthpiece portion 130 is provided in the detachable capsule 106 , the inhalation device 100 can be kept clean.

When the user holds the mouthpiece portion 130 in the mouth and performs an inhalation operation, air flows into the channel 128 of the atomizer 104 via an opening (not shown), and an aerosol generated by heating the aerosol source by the heater 127 is transported to the mouthpiece portion 130 , as indicated by arrows. In the arrangement in which the flavor source 131 is arranged, a flavor substance generated from the flavor source 131 is added to the aerosol, transported to the mouthpiece portion 130 , and inhaled into the mouth of the user.

FIG. 2 shows the first arrangement example of the electric component 110 . The electric component 110 can include a power supply (battery) 250 , a power supply unit (power supplier) 270 that supplies power to (the heater 127 of) the atomizer 104 , a detection circuit 220 configured to detect the resistance value of the heater 127 , and a processor 240 that generates a control signal in accordance with information obtained using the detection circuit 220 . The heater 127 has a resistance value R HTR that changes depending on the temperature of the heater 127 .

The power supply unit 270 can include a switch SW 1 arranged in a current path configured to supply a current to the heater 127 . Opening/closing (off/on) of the switch SW 1 can be controlled by a control signal SWC 1 generated by the processor 240 . The power supply unit 270 can include, for example, a voltage converter 272 that converts a power supply voltage V bat supplied from the power supply 250 into a heater driving voltage V out . The switch SW 1 can be arranged to form a current path configured to supply a current to the heater 127 between the ground line and the supply line of the heater driving voltage V out . The switch SW 1 can be arranged, for example, between the heater 127 and the supply line of the heater driving voltage V out .

The detection circuit 220 can include a shunt resistor R shunt1 and a switch SW 2 , which are arranged, in series with the heater 127 , between the ground line and the supply line of the heater driving voltage V out . Also, the detection circuit 220 can include an amplifier AMP that detects a voltage V HTR applied to the heater 127 . Here, the resistance value of the shunt resistor R shunt1 will be expressed as R shunt1 , like the reference symbol. The amplifier AMP includes, for example, a differential amplifier 221 including a noninverting input terminal, an inverting input terminal, and an output terminal, a resistive element R 1 that connects the inverting input terminal and the ground line, and a resistive element R 2 that connects the inverting input terminal and the output terminal, and the voltage V HTR can be input to the noninverting input terminal. In this arrangement example, if the resistance value of the resistive element R 1 is expressed as R 1 , and the resistance value of the resistive element R 2 is expressed as R 2 , an amplification factor A of the amplifier AMP is (1+R 2 /R 1 ). The switch SW 2 can be controlled by a control signal SWC 2 generated by the processor 240 .

To detect the resistance value R HTR of the heater 127 , the switch SW 1 is turned off, and the switch SW 2 is turned on. At this time, letting I HTR be a current flowing to R HTR , equation (1) is obtained. R HTR =V HTR /I HTR =V HTR ·( R HTR +R shunt1 )/ V out (1) When equation (1) is deformed, equation (2) for gibing R HTR is obtained. R HTR =R shunt1 ·V HTR /( V out −V HTR ) (2)

An output voltage V AMP of the amplifier AMP of the detection circuit 220 is given by V AMP =A·V HTR (3) When equation (3) is deformed, equation (4) for giving V HTR is obtained. V HTR =V AMP /A (4)

Hence, the resistance value R HTR of the heater 127 can be obtained in accordance with equations (2) and (4).

The processor 240 can include an input terminal to which the output voltage V AMP of the amplifier AMP of the detection circuit 220 is input, and an A/D converter that converts an analog signal that is a voltage input to the input terminal into a digital signal. The processor 240 can generate a control signal in accordance with information (here, V AMP ) obtained using the detection circuit 220 . The control signal can be, for example, the control signal SWC 1 but can include another control signal (for example, a control signal that controls the display unit DISP).

The processor 240 can be formed by, for example, an MCU (Micro Controller Unit). However, the processor 240 may be formed by an MCU and an analog circuit. To the processor 240 , a voltage V mcu can be supplied from a voltage conversion circuit 260 such as an LDO (Low DropOut) that converts the power supply voltage V bat into the voltage V mcu for the processor 240 . The processor 240 can calculate the resistance value R HTR of the heater 127 in accordance with equations (2) and (4) based on R shunt1 that is a known value, V out , and V AMP that is supplied from the amplifier AMP.

The processor 240 can calculate the temperature of the heater 127 in accordance with equation (5) based on the resistance value R HTR of the heater 127 . T=T ref +(1/α)·( R HTR −R ref )·(1/ R ref )·10 6 (5)

In equation (5), T ref is the reference temperature of the heater 127 . R ref is the reference resistance value of the heater 127 , and this is the resistance value R HTR of the heater 127 at the reference temperature. α is the temperature coefficient [ppm/° C.] of the heater 127 . Here, the reference temperature can be an arbitrary temperature, and can be stored in the memory of the processor 240 in association with (in linkage with) the reference resistance value. As the reference temperature, for example, a temperature set in advance may be used, as will be described later, or the temperature of the heater 127 obtained when acquiring the reference resistance value may be used. The temperature of the heater 127 obtained when acquiring the reference resistance value can be converted from the temperature of an arbitrary portion in the inhalation device 100 (for example, a temperature detected by a temperature sensor 282 to be described later).

Based on the temperature of the heater 127 , the processor 240 can generate the control signal SWC 1 used to control the switch SW 1 such that the temperature of the heater 127 matches a target temperature. The processor 240 receives a signal from the operation unit OP of the user interface 116 , and provides a signal for display control to the display unit DISP of the user interface 116 . The electric component 110 can include a puff sensor (for example, a pressure sensor) 281 that detects the puff operation of the user, and the temperature sensor 282 that detects the temperature of a predetermined portion of the electric component 110 . The temperature sensor 282 may be incorporated in the puff sensor 281 , the power supply 250 , or the processor 240 .

FIG. 3 is a view showing the second arrangement example of the electric component 110 . The second arrangement example is different from the first arrangement example in that a shunt resistor R shunt2 is provided, in series with the shunt resistor R shunt1 , between a shunt resistor R shunt1 and the ground line, and the rest is the same as in the first arrangement example. Here, the resistance value of the shunt resistor R shunt2 will be expressed as R shunt2 , like the reference symbol. The resistance value R shunt2 is sufficiently larger than the resistance value R HTR . Hence, equation (2) can be used in the calculation of the resistance value R HTR .

FIG. 4 is a view showing the third arrangement example of the electric component 110 . The third arrangement example is different from the first arrangement example in that the voltage V mcu is supplied to the power supply terminal of the differential amplifier 221 . The shunt resistor R shunt2 as in the second arrangement example may be added to the third arrangement example. Between the noninverting input terminal and the output terminal of the differential amplifier 221 , a diode can be arranged in the forward direction from the noninverting input terminal to the output terminal.

FIGS. 5 A- 5 B show the operation of the inhalation device 100 . This operation is controlled by the processor 240 . The processor 240 includes a memory that stores a program, and a CPU that operates in accordance with the program. In step S 501 , the processor 240 waits for reception of an atomization request, and upon receiving an atomization request, executes step S 502 . The atomization request is a request for operating the atomizer 104 , more specifically, controlling the heater 127 within a target temperature range to generate an aerosol from the aerosol source. The atomization request can be an operation of detecting, by the puff sensor 281 , that the user has performed the inhalation operation (puff operation) via the mouthpiece portion 130 , and notifying, by the puff sensor 281 , the processor 240 of the detection (for example, transmission of a detection signal). Alternatively, the atomization request can be an operation of notifying, by the operation unit OP, the processor 240 that the user has operated the operation unit OP (for example, transmission of an operation signal). In the following description, during the inhalation operation of the user or during the operation of the operation unit OP by the user, the atomization request is continuously transmitted from the puff sensor 281 or the operation unit OP, and when the user ends the inhalation operation or the operation of the operation unit OP, (transmission of) the atomization request is ended.

In step S 502 , the processor 240 acquires the power supply voltage V bat from a power supply management circuit (not shown), and determines whether the power supply voltage V bat is higher than a discharge end voltage V end (for example, 3.2 V). That the power supply voltage V bat is equal to or lower than the discharge end voltage V end means that the remaining dischargeable amount of the power supply 250 is not sufficient. Hence, if the power supply voltage V bat is equal to or lower than the discharge end voltage V end , in step S 519 , the processor 240 makes a notification to promote charge of the power supply 250 using the display unit DISP of the user interface 116 . If the display unit DISP includes an LED, this notification can be causing the LED to light in red. On the other hand, if the power supply voltage V bat is higher than the discharge end voltage V end , the processor 240 executes heating processing. Heating processing is processing of controlling the power supply unit 270 to supply power to the heater 127 and heating the aerosol source in accordance with reception of the aerosol source atomization request, and can include steps S 503 to S 507 .

In step S 503 , using the display unit DISP of the user interface 116 , the processor 240 can make a notification representing that a normal operation is possible. If the display unit DISP includes an LED, this notification can be causing the LED to light in blue. Next, in step S 504 , the processor 240 starts power feeding control (power supplying control) for the heater 127 . The power feeding control for the heater 127 includes temperature control of controlling the heater 127 within a target temperature range. The temperature control can include feedback control of detecting the temperature of the heater 127 by detecting the resistance value R HTR of the heater 127 , and controlling opening/closing of the switch SW 1 by the control signal SWC 1 based on the detection result.

Next, in step S 505 , the processor 240 resets an inhalation time T L to 0. After that, in step S 506 , the processor 240 adds Δt to the inhalation time T L . Δt corresponds to the time interval between execution of step S 506 and the next execution of step S 506 .

Next, in step S 507 , the processor 240 determines whether the atomization request has ended. If the atomization request has ended, in step S 509 , the processor 240 stops the power feeding control for the heater 127 . On the other hand, if the atomization request has not ended, in step S 508 , the processor 240 determines whether the inhalation time T L has reached an upper limit time. If the inhalation time T L has not reached the upper limit time, the process returns to step S 506 . As an example, the upper limit time may be 2.0 to 2.5 sec.

Next to step S 509 , in step S 510 , the processor 240 turns off the LED that is lighting in blue. Next, in step S 511 , the processor 240 updates an integrated time T A . More specifically, in step S 511 , the inhalation time T L is added to the integrated time T A at the current point of time. The integrated time T A can be an integrated time when the capsule 106 was used for inhalation, in other words, an integrated time when the aerosol was inhaled via the flavor source 131 of the capsule 106 .

In step S 512 , the processor 240 determines whether the integrated time T A is not more than an inhalation enable time (for example, 120 sec). If the integrated time T A is not more than the inhalation enable time, this means that the capsule 106 can still provide the flavor substance. In this case, the process returns to step S 501 . If the integrated time T A is more than the inhalation enable time, in step S 513 , the processor 240 waits for generation of the atomization request. If the atomization request is generated, in step S 514 , the processor 240 waits for continuation of the atomization request for a predetermined time. After that, in step S 515 , the processor 240 inhibits power feeding control for the heater 127 . Note that step S 514 may be omitted.

Next, in step S 516 , using the display unit DISP of the user interface 116 , the processor 240 can make a notification to promote exchange of the capsule 106 . If the display unit DISP includes an LED, this notification can be causing the LED to blink in blue (repeat on/off). Hence, the user can exchange the capsule 106 . In an example, one atomizer 104 and a plurality of (for example, three) capsules 106 can be sold as one set. In this example, after one atomizer 104 and all capsules 106 in one set are consumed, the atomizer 104 and the last capsule 106 in the consumed set can be exchanged with an atomizer 104 and a capsule 106 of a new set.

In step S 517 , the processor 240 waits for completion of the exchange of the capsule 106 (or the capsule 106 and the atomizer 104 ). In step S 518 , the processor 240 cancels inhibition of the power feeding control for the heater 127 and returns to step S 501 .

Detection associated processing concerning detection of the resistance value R HTR of the heater 127 and detection of the temperature of the heater 127 based on that will be described below. FIGS. 6 A- 6 B show detection associated processing. Detection associated processing is executed by the processor 240 separately from the processing shown in FIGS. 5 A- 5 B . The power feeding control described with reference to FIGS. 5 A- 5 B can be executed based on the temperature of the heater 127 acquired by detection associated processing shown in FIGS. 6 A- 6 B .

In step S 601 , the processor 240 determines whether an atomization request is received. If an atomization request is received, the process advances to step S 602 . If an atomization request is not received, the process advances to step S 621 . In step S 602 , the processor 240 determines whether Count that is a variable for control is equal to or larger than a predetermined number (for example, 3). If Count is equal to or larger than the predetermined number, the process advances to step S 616 . Otherwise, the process advances to step S 603 . Count is a variable that is incremented every time it is detected that the temperature of the heater 127 exceeds 250° C. That Count is equal to or larger than the predetermined number indicates that the aerosol source in the container 125 of the atomizer 104 is nearly exhausted or is completely exhausted. The value of the predetermined number can be determined in consideration of the detection error (including the influence of noise) of the temperature of the heater 127 , and the like.

Steps S 603 to S 611 are processes performed during execution of heating processing (steps S 503 to S 507 in FIGS. 5 A- 5 B ). In step S 603 , the processor 240 turns on the switch SW 1 . In step S 604 , the processor 240 turns on the switch SW 2 . Next, in step S 605 , the processor 240 turns off the switch SW 1 . In this state, the resistance value R HTR of the heater 127 can be detected. In step S 606 , the processor 240 calculates the resistance value R HTR of the heater 127 in accordance with equations (2) and (4) based on the output voltage V AMP of the amplifier AMP of the detection circuit 220 .

In step S 607 , the processor 240 calculates the resistance value R HTR of the heater 127 in accordance with equation (5) based on the resistance value R HTR of the heater 127 calculated in step S 606 and reference temperature T ref and the reference resistance value R ref that are already set. Steps S 606 and S 607 correspond to processing of acquiring the temperature of the heater 127 based on the reference resistance value R ref and the information obtained using the detection circuit 220 . In step S 608 , the processor 240 turns off the switch SW 2 .

In step S 609 , the processor 240 determines whether a temperature T HTR of the heater 127 exceeds 300° C. If the temperature T HTR exceeds 300° C. (the second temperature or the second threshold), the process advances to step S 616 . If the temperature T HTR is equal to or lower than 300° C., the process advances to step S 610 . In step S 610 , the processor 240 determines whether the temperature T HTR of the heater 127 exceeds 250° C. (the first temperature or the first threshold). If the temperature T HTR exceeds 250° C., the process advances to step S 625 . If the temperature T HTR is equal to or lower than 250° C., the process advances to step S 611 . In step S 625 , the processor 240 sets a flag Flag (that is, Flag=true). In this example, that the temperature T HTR of the heater 127 exceeds 250° C. (first temperature) indicates that the aerosol source in the container 125 of the atomizer 104 is nearly exhausted. That the temperature T HTR of the heater 127 exceeds 300° C. (second temperature) indicates that the aerosol source is completely exhausted. However, the first temperature and the second temperature can arbitrarily be determined in accordance with the type of the aerosol source, the structure of the transport portion (wick) 126 , and the like.

In step S 611 , the processor 240 determines whether the atomization request has ended. If the atomization request has ended, the process advances to step S 612 . If the atomization request has not ended, the process returns to step S 603 . In step S 612 , the processor 240 determines whether the flag Flag is set. If the flag Flag is set, the process advances to step S 626 . If the flag Flag is not set, the process advances to step S 613 . That the flag Flag is set indicates that the temperature T HTR of the heater 127 exceeds 250° C.

In step S 613 , the processor 240 performs cooling determination processing of determining whether natural cooling of the heater 127 is completed. If a predetermined time has elapsed from the end of heating processing (that is, from the end of step S 611 ), the processor 240 may determine that natural cooling of the heater 127 is completed. Alternatively, the processor 240 may detect the resistance value R HTR of the heater 127 and determine, based on the resistance value R HTR , that natural cooling of the heater 127 is completed. A detailed example of step S 613 will be described later.

Next to step S 613 , in step S 614 , the processor 240 detects the resistance value R HTR of the heater 127 using the detection circuit 220 , and updates the reference resistance value R ref by the resistance value R HTR . More specifically, the processor 240 turns on the switch SW 2 , detects the output voltage V AMP of the amplifier AMP, and after that, turns off the switch SW 2 . The processor 240 calculates the resistance value R HTR of the heater 127 in accordance with equations (2) and (4) based on the detected output voltage V AMP , and stores the calculated resistance value R HTR as the reference resistance value R ref in the memory in association with (in linkage with) the reference temperature T ref . In step S 615 , the processor 240 resets Count to 0.

The reference resistance value R ref at the reference temperature T ref can vary in, for example, each inhalation operation (puff operation) of the user because of the contact resistance between the electrical contact ( 111 , 112 ) of the holding portion 103 of the controller 102 and the electrical contact ( 123 , 124 ) of the heater 127 , oxidation of the heater 127 , and the like. For this reason, in step S 614 , the resistance value R HTR of the heater 127 is detected after the end of heating processing and before reception of the next atomization request, and the reference resistance value R ref is updated by the resistance value R HTR , thereby accurately acquiring the temperature of the heater 127 during heating processing. In addition, step S 614 is performed after it is determined in step S 613 that natural cooling of the heater 127 is completed, that is, in a state in which the heater 127 is sufficiently naturally cooled, and the temperature of the heater 127 is stable. That is, since the resistance value R HTR is detected in a state in which the time fluctuation of the resistance value R HTR of the heater 127 is small and stable, the reliable reference resistance value R ref can be acquired.

Here, as the reference temperature T ref stored in the memory in association with the reference resistance value R ref , for example, a constant (temperature) already stored in the memory as the reference temperature T ref may be used. In this case, the constant can arbitrarily be set by pre-verification or the like and is preferably set to a temperature higher than 27° C. that is generally called room temperature (R.T.). This is because a long time is needed to lower the temperature T HTR of the heater 127 to the room temperature (27° C.) by natural cooling. For example, the constant is set to an arbitrary temperature within the range of 30° C. to 50° C. or preferably to an arbitrary temperature within the range of 35° C. to 45° C., and is 40° C. as an example.

Alternatively, as the reference temperature T ref stored in the memory in association with the reference resistance value R ref , for example, a temperature calculated based on the output value of the temperature sensor 282 may be used. In this case, since the temperature sensor 282 detects the temperature of a component different from the heater 127 , a correction value used to calculate (convert) the temperature of the heater 127 after cooling from the output value of the temperature sensor 282 (the temperature of the component) is preferably obtained by pre-verification. The correction value may have a form of a coefficient to be multiplied by the output value of the temperature sensor 282 , or may have a form of a constant to be added to the output value. Note that the temperature sensor 282 may be a temperature sensor configured to detect the temperature of the power supply (battery) 250 , as described above, or may be a temperature sensor provided in the puff sensor 281 to output a temperature-compensated pressure value. The temperature sensor of the puff sensor 281 can detect an outside air temperature.

If the processor 240 determines in step S 609 that the temperature T HTR of the heater 127 exceeds 300° C., in step S 616 , the processor 240 makes a notification representing the occurrence of an abnormality (exhaustion of the aerosol source) using the display unit DISP of the user interface 116 . If the display unit DISP includes an LED, this notification can be causing the LED to blink in red (repeat on/off).

Next, in step S 617 , the atomization request is masked (disabled). In a state in which the atomization request is masked, even if an atomization request is generated, it is neglected. That is, in a state in which the atomization request is masked, even if an atomization request is generated, it is determined in step S 601 (also in step S 501 of FIGS. 5 A- 5 B ) that the atomization request does not exist. Next, in step S 618 , the processor 240 determines whether the time (non-operation time) in which an operation by the user on the operation unit OP of the user interface 116 is not performed has reached a predetermined time (for example, 6 min). If the non-operation time has reached the predetermined time, the processor 240 transitions to a sleep state (sleep mode). Return from the sleep state can be done in response to, for example, an operation by the user on the operation unit OP of the user interface 116 .

Until the non-operation time reaches the predetermined time, step S 619 is executed. In step S 619 , the processor 240 waits for completion of the exchange work of the atomizer 104 . More specifically, in step S 619 , the processor 240 waits for an operation of detaching the atomizer 104 from (the holding portion 103 of) the controller 102 and attaching a new atomizer 104 to (the holding portion 103 of) the controller 102 . The processor 240 can determine completion of the exchange work of the atomizer 104 based on a change in the output voltage V AMP of the amplifier AMP of the detection circuit 220 .

Here, when the atomizer 104 is detached from the holding portion 103 , the heater 127 connected between the first electrical contact 111 and the second electrical contact 112 is lost. Hence, the output voltage V AMP of the amplifier AMP changes. Based on this, the processor 240 can detect the detachment of the atomizer 104 from the holding portion 103 . When the atomizer 104 is attached to the holding portion 103 , the heater 127 is connected between the first electrical contact 111 and the second electrical contact 112 . Hence, the output voltage V AMP of the amplifier AMP changes. Based on this, the processor 240 can detect that the atomizer 104 is attached to the holding portion 103 .

Upon detecting the exchange of the atomizer 104 , in step S 620 , the processor 240 resets Count to 0 and clears Flag. Next, in step S 621 , the processor 240 detects the output voltage V AMP of the amplifier AMP, calculates the resistance value R HTR of the heater 127 in accordance with equations (2) and 4 based on the output voltage V AMP , and stores the resistance value R HTR in the memory as the reference resistance value R ref . Step S 621 is processing of acquiring the reference resistance value R ref of the heater 127 of the atomizer 104 newly attached to (the holding portion 103 of) the controller 102 . In the new atomizer 104 , the characteristic (for example, the relationship between the reference temperature and the reference resistance value) of the heater 127 may be different from that in the atomizer 104 used so far because of a manufacturing error or individual difference. Hence, when step S 621 is performed, the resistance value R HTR of the heater 127 of the atomizer 104 newly attached to the controller 102 can be detected as the reference resistance value R ref in a state in which power feeding is not performed yet (heating is not performed).

In step S 622 , the processor 240 acquires the temperature of a predetermined portion of the inhalation device 100 from the temperature sensor 282 , and stores the temperature in the memory as the reference temperature T ref . Here, a temperature difference may exist between the heater 127 and the predetermined portion of the inhalation device 100 . Such a temperature difference may be neglected, or the temperature difference may be eliminated by the above-described correction value. Next, in step S 623 , masking of the atomization request is canceled.

In step S 624 , the processor 240 determines whether the non-operation time in which an operation by the user on the operation unit OP of the user interface 116 is not performed has reached a predetermined time (for example, 6 min). If the non-operation time has reached the predetermined time, the processor 240 transitions to the sleep state (sleep mode). On the other hand, if the non-operation time has not reached the predetermined time, the process returns to step S 601 .

If the flag Flag is set in step S 612 described above, the process advances to step S 626 . In step S 626 , the processor 240 makes a notification representing the occurrence of an abnormality (temporary shortage of the aerosol source in the transport portion (wick) 126 ) using the display unit DISP of the user interface 116 . If the display unit DISP includes an LED, this notification can be causing the LED to blink in red (repeat on/off). Next, in step S 627 , the processor 240 masks (disables) the atomization request. In step S 628 , the processor 240 inhibits heating of the heater 127 (power feeding to the heater 127 ) for a predetermined period (for example, 11 sec). Next, the processor 240 cancels masking of the atomization request in step S 629 , increments Count in step S 630 , and returns to step S 618 .

Details of cooling determination processing of step S 613 in FIGS. 6 A- 6 B will be described with reference to FIGS. 7 to 12 . FIGS. 7 and 8 show verification examples of the temporal changes (time-rate changes) of the temperature and the resistance value of the heater 127 during and after execution of heating processing of the heater 127 (feeding to the heater 127 ). In FIGS. 7 and 8 , the period of 0 to 3 sec is the period in which the heating processing of the heater 127 is being executed, and the period after the period of 3 sec is the period in which the heating processing of the heater 127 is ended, and natural cooling is performed. In FIGS. 7 and 8 , the resistance value of the heater 127 (the ordinate on the right side) is a value calculated in accordance with equations (2) and (4) based on the output voltage V AMP of the amplifier AMP, and the temperature of the heater 127 (the ordinate on the left side) is a value calculated in accordance with equation (5) based on the calculated resistance value.

FIG. 7 shows an example in which verification of the temporal changes of the temperature and the resistance value of the heater 127 was performed a plurality of times (four times) in a state in which the aerosol source sufficiently existed in the container 125 of the atomizer 104 , and the aerosol source was sufficiently supplied to the transport portion (wick) 126 . In the example shown in FIG. 7 , it is found that the temperature of the heater 127 during execution of heating processing (the period of 0 to 3 sec) is about 200° C. in the four verifications. FIG. 9 is an enlarged view showing the temporal changes of the temperature and the resistance value of the heater 127 under natural cooling after the end of heating processing (during the period after the period of 3 sec). It can be seen that the temporal changes of the temperature and the resistance value of the heater 127 stabilize about 10 sec after the end of heating processing (that is, about 13 sec after the start of heating processing). Here, the stabilization of the temporal change of the resistance value of the heater 127 can arbitrarily be defined, and may be defined as a state in which, for example, the temporal change ratio (gradient) of the resistance value of the heater 127 falls within an allowable range (for example, 10 mΩ/sec or less). As an example, it may be defined as a state in which the difference between the maximum resistance value and the minimum resistance value of the heater 127 during a predetermined time (for example, 3 sec) falls within an allowable range (for example, 10 mΩ/sec or less).

FIG. 8 shows an example in which verification of the temporal changes of the temperature and the resistance value of the heater 127 was performed a plurality of times in a state in which the aerosol source in the container 125 of the atomizer 104 was nearly exhausted, and the transport portion (wick) 126 started drying. In the example shown in FIG. 8 , it is found that since the transport portion 126 dries along with an increase in the verification count, the temperature of the heater 127 increases during execution of heating processing (the period of 0 to 3 sec). FIG. 10 is an enlarged view showing the temporal changes of the temperature and the resistance value of the heater 127 under natural cooling after the end of heating processing (during the period after the period of 3 sec). It can be seen that the temporal changes of the temperature and the resistance value of the heater 127 stabilize about 10 sec after the end of heating processing (that is, about 13 sec after the start of heating processing). It is found that the resistance value converges to almost the same resistance value irrespective of the verification count.

According to the above-described verifications, it can be seen that when a predetermined time (for example, 10 sec) elapses from the end of heating processing, the resistance value converges to almost the same resistance value, and the temporal change of the resistance value of the heater 127 stabilizes regardless of the amount of the aerosol source in the container 125 . That is, cooling determination processing (step S 613 ) is preferably executed such that detection of the resistance value R HTR of the heater 127 as the reference resistance value R ref (step S 614 ) is executed after the elapse of a predetermined time from the end of heating processing.

FIG. 11 shows the first example for providing details of cooling determination processing of step S 613 in FIGS. 6 A- 6 B . In step S 701 , the processor 240 activates a timer. For example, upon determining in step S 611 that the atomization request has ended (that is, at the end of heating processing), the processor 240 activates the timer. In step S 702 , the processor 240 determines whether a preset predetermined time has elapsed, and if the predetermined time has elapsed, advances to step S 614 in FIGS. 6 A- 6 B . The predetermined time can be set to a time (for example, 10 sec) in which the temporal change of the resistance value of the heater 127 stabilizes in natural cooling after the end of heating processing, as described above.

FIG. 12 shows the second example for providing details of cooling determination processing of step S 613 in FIGS. 6 S- 6 B . In step S 801 , the processor 240 activates a timer. For example, upon determining in step S 611 that the atomization request has ended (that is, at the end of heating processing), the processor 240 activates the timer. Next, in step S 802 , the processor 240 starts detecting the resistance value R HTR of the heater 127 . In step S 803 , the processor 240 starts monitoring the temporal change ratio (time-rate change ratio) of the resistance value R HTR of the heater 127 . For example, the processor 240 turns on the switch SW 2 , detects the output voltage V AMP of the amplifier AMP, and calculates the resistance value R HTR of the heater 127 in accordance with equations (2) and (4) based on the output voltage V AMP . The processor 240 performs detection (calculation) of the resistance value R HTR of the heater 127 periodically (for example, at a period of 10 msec), and stores the detected resistance value R HTR of the heater 127 in the memory in linkage with the elapsed time from the end of heating processing.

Next, in step S 804 , the processor 240 determines whether the temporal change ratio of the resistance value R HTR of the heater 127 falls within an allowable range. As an example, the processor 240 determines whether the difference between a maximum resistance value MAX(R HTR ) and a minimum resistance value MIN(R HTR ) of the heater 127 during the time between the current time and a time retroactive from the current time by a predetermined time (for example, 3 sec) falls within an allowable range (for example, 10 mΩ or less). Step S 803 is executed until the difference falls within the allowable range. On the other hand, if the difference falls within the allowable range, in step S 805 , the processor 240 ends monitoring the temporal change ratio of the resistance value R HTR of the heater 127 and then advances to step S 614 in FIGS. 6 A- 6 B .

Here, in the second example shown in FIG. 12 , the above-described first example shown in FIG. 11 may be applied. More specifically, step S 702 of the first example shown in FIG. 11 may be applied between step S 801 and step S 802 of the second example shown in FIG. 12 . In this case, step S 802 is executed after the elapse of a predetermined time (for example, 10 sec) from the end of heating processing. Since this decreases the number of times of energizing the heater 127 to acquire the resistance value R HTR of the heater 127 , the time until affirmative determination is done in step S 804 can be shortened.

<Another Example of Detection Associated Processing>

Another example of detection associated processing concerning detection of the resistance value R HTR of the heater 127 and detection of the temperature of the heater 127 based on that will be described next. FIGS. 13 A- 13 B show another example of detection associated processing. The flowcharts of FIGS. 13 A- 13 B are basically the same as the flowcharts of FIGS. 6 A- 6 B except that steps S 631 and S 632 are further added. Note that in the example shown in FIGS. 13 A- 13 B , both steps S 631 and S 632 are executed. However, the present invention is not limited to this, and one of steps S 631 and S 632 may be executed.

Step S 631 is arranged between step S 630 and step S 618 . In step S 631 , the processor 240 detects the resistance value R HTR of the heater 127 using the detection circuit 220 , and updates the reference resistance value R ref by the resistance value R HTR , as in step S 614 . Since step S 631 is performed after step S 628 of inhibiting heating of the heater 127 for a predetermined period (for example, 11 sec), the heater 127 is sufficiently cooled, and the temperature of the heater 127 is stabilized. Hence, when the reference resistance value R ref is updated by the resistance value R HTR of the heater 127 detected in this state, the reliable reference resistance value R ref can be acquired. Note that step S 631 need not always be arranged between step S 630 and step S 618 , and can be executed at an arbitrary timing after step S 628 and before the next atomization request. Step S 631 may be executed during step S 628 (that is, during a predetermined time in which heating of the heater 127 is inhibited). In this case, step S 631 is preferably executed after stabilization of the temperature of the heater 127 (for example, after waiting for the time (about 10 sec) set in advance to stabilize the temperature of the heater 127 ), and is particularly preferably executed immediately before the elapse of a predetermined time in step S 628 . After the time of about 10 sec elapses from the end of heating processing, the temporal changes of the temperature and the resistance value of the heater 127 stabilize, as described above. Hence, even before the elapse of the predetermined time in step S 628 , the reliable reference resistance value R ref can be acquired.

Step S 632 is executed before the transition to the sleep state (sleep mode) if it is determined in step S 618 or S 624 that the non-operation time has reached a predetermined time (for example, 6 min). In step S 632 as well, the processor 240 detects the resistance value R HTR of the heater 127 using the detection circuit 220 , and updates the reference resistance value R ref by the resistance value R HTR , as in step S 614 or S 631 . Since the heater 127 is sufficiently cooled, and the temperature of the heater 127 is stabilized even at the timing of transition to the sleep state, the reliable reference resistance value R ref can be acquired.

Operation modes of the processor 240 will be described here. FIG. 14 shows an example of operation modes of the processor 240 . The processor 240 can include, as operation modes, for example, a power mode 901 , a sleep mode 902 , an inhalation mode 903 , and a charge mode 904 . The above-described processes shown in FIGS. 5 A- 5 B, 6 A- 6 B, and 13 A- 13 B can be executed in the states of the power mode 901 and the inhalation mode 903 . The power mode 901 is a state in which power feeding to the puff sensor 281 is being performed, and is a mode (first mode) in which heating processing can be executed in accordance with reception of an atomization request. In the state of the power mode 901 , the puff sensor 281 detects that the user performs the inhalation operation via the mouthpiece portion 130 . Upon receiving an atomization request from the puff sensor 281 , the processor 240 transitions from the power mode 901 to the inhalation mode 903 . The inhalation mode 903 is a mode in which heating processing is executed by supplying power to the heater 127 . When the atomization request ends, the processor 240 transitions from the inhalation mode 903 to the power mode 901 .

If the non-operation time has reached a predetermined time (for example, 6 min), the processor 240 transitions from the power mode 901 to the sleep mode 902 . The sleep mode 902 is a mode (second mode) in which power feeding to the puff sensor 281 is stopped to make power consumption smaller than in the power mode 901 . If an operation by the user on the operation unit OP (for example, long press on the operation unit OP (switch) by the user) is detected, the processor 240 transitions from the sleep mode 902 to the power mode 901 .

The charge mode 904 is a mode in which the power supply (battery) 250 is charged. If a charger is connected to a charge port (for example, a USB port) provided in the controller 102 , the processor 240 transitions from the sleep mode 902 to the charge mode 904 . On the other hand, if the charger is detached from the charge port of the controller 102 , the processor 240 transitions from the charge mode 904 to the sleep mode 902 . In addition, if an operation of the user (for example, long press on the operation unit OP by the user) is detected in a state in which the charger is connected to the charge port of the controller 102 (the state of the charge mode 904 ), the processor 240 interrupts charge of the power supply 250 and transitions from the charge mode 904 to the power mode 901 . If the atomization request has ended in this case, the processor 240 transitions from the power mode 901 to the charge mode 904 to resume charge of the power supply 250 .

OTHER EMBODIMENTS

Calculations exemplified by equations (2) and (4) may be implemented by an analog circuit. FIG. 15 shows an analog circuit that calculates the resistance value R HTR of the heater 127 in accordance with equations (2) and (4). Such an analog circuit may be incorporated in the MCU that constitutes the processor 240 or may be provided separately from the MCU. In detection associated processing shown in FIGS. 6 and 13 , the temperature T HTR of the heater 127 is calculated in step S 607 based on the resistance value R HTR of the heater 127 calculated in step S 606 . However, step S 607 may be omitted. Note that in this case, each of the second temperature in step S 609 and the first temperature in step S 610 needs to be converted into a resistance value using equation (5). That is, in step S 609 , the processor 240 determines whether the resistance value R HTR of the heater 127 calculated in step S 606 exceeds the resistance value converted from the second temperature (300° C.). Additionally, in step S 610 , the processor 240 determines whether the resistance value R HTR of the heater calculated in step S 606 exceeds the resistance value converted from the first temperature (250° C.).

The invention is not limited to the foregoing embodiments, and various variations/changes are possible within the spirit of the invention.